Elendur was the eldest son and heir of Isildur, slain with his father in the Disaster of the Gladden Fields. He was also the most trusted son of Isildur, being the only son with knowledge of the One Ring borne by Isildur. Elendur was often said to be remarkably similar to Elendil, his grandfather.[1]

Knowing of the Ring, Elendur argued with his father. Though Isildur had sent Ohtar away to preserve the shards of Narsil, the King still bore the Elendilmir and the Ring. Elendur thought is was wise for his father to flee and abandon them: Ciryon was dead and Aratan was dying, and orcs overran them from all sides. Isildur did eventually flee, but was pierced by arrows after he swam across the Anduin. Elendur took command of what remained, and was slain with his troops.[1]